Honing apparatus



April 30, 1957 G. M. CALVERT HONING APPARATUS 2 Sheets-Sheet 1 Filed Nov. 1, 1954 INVENTOR.

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April 30, 1957 G. M. CALVERT 2,

HONING APPARATUS Filed Nov. 1, 1954 2 Shets-Sheet 2 United States Patent.

HONING APPARATUS Glen M. Calvert, Detroit, Mich.

Application November 1, 1954, Serial No. 465,887

18 Claims. (Cl. 51- 184.3)

This invention relates to honing apparatus and particularly to improvements adapted to be embodied in a honing tool for accomplishing such important objects and functions as accurately gauging the diameter of a workpiece bore and interrupting the honing operation immediately upon the finishing of the bore to the desired diameter, controlling the operation of the gauge orsizing means so as to compensate for wearthereof, holding and maintaining the workpiece in proper relation to the honing tool during the honing operation, improving the action of the honing or abrading stones, and improving the construction of the abrading elements so as to prolong materially the life of the stones. These important objects are accomplished by means of honing apparatus which may be constructed in accordance with the embodiments of the invention herein illustrated.

Honing apparatus embodying the present invention may be used for honing the bores of various types of workpieces, such as connecting rods, .gears, cylinders etc. for internal combustion engines. The illustrated mechanism is especially adapted for honing relatively small diameter bores or the bores of workpieces, such as connecting rods, which present problems in respect to maintaining the workpiece in a true position relative to the honing tool. The apparatus comprises a spindle which may be disposed vertically or at an angle to the vertical or horizontally, the spindle being drivingly connected at its inner or upper end to a machine head which is capable of imparting a combined'rotative and reciprocating movement to the spindle. The spindle is provided at its outer or lower end with an abrading head having abrading elements, such as holders carrying abrading stones, spaced equally around the head and adapted to be moved outwardly or expanded radially against the surface of the workpiece bore by a cone member or wedge device attached to a rod or shaft extending through the spindle bore and shiftable axially thereof by suitable means, such as hydraulic mechanism conventionally used for this purpose in honing machines. With the abrading elements expanded outwardly against the workpiece bore, rotary and reciprocating movements applied to the spindle will result in honing the bore and the removal of material or stock therefrom.

In accordance with the present embodiments the honing tool is provided with gauge or sizing means having gauge portions or elements adapted to enter the workpiece bore when finish honed to the desired diameter. As soon as this occurs the gauge means functions to interrupt the honing operation by causing retraction of the cone carrying member thereby resulting in' the collapse of the abrading elements and preventing the bore from being honed beyond the desired size as determined by the diametric dimensions of the gauge means. In order to achieve very accurate gauging of the finished bore the gauge means, which preferably includes a sizing or gauging ring or sleeve embracing the tool spindle, is mounted so as to be free to shift or float laterally relative to the spindle. This construction is important in that it enables the 2,790,217 Patented Apr. 30, 1957 gauge ring to center itself with the center of the workpiece bore thereby compensating for misalignment between the axis of the toolspindle and the central axis-of the workpiece bore. By thus compensating for misalignment the gauge ring or gauging means will enter the bore when honed to the desired diameter andasaconsequence obviating honing of the bore to any appreciable oversize or to oversize beyond allowable tolerances.

The gauging means or sizing ring preferably is provided with a number, preferably four, hardened or wear resisting inserts or elements which contact the edge of the workpiece bore when attempting to enter the bore. These gauge elements terminate in tapered lead portions which contact the edge of the bore and serve'in effect'a's ameans to shift the gauge ring laterally by a camming action thereby centering the ring with the workpiece. The gauge means is urged in the direction of entering the bore by resilient means, such as a compression spring, and the effort exerted by this spring serves to cause oneor more of the tapered lead portions, engaging the edge of the bore during the honing operation, to shift'or displace the gauge means laterally until centered with the workpiece bore and also to force the gauge means into the bore when finished to the desired size.

Although the gauge means or the elements, which efiect the sizing of the bore, are precision machined or formed with the view to accuracy in dimensions and are hardened or wear resisting, yet in practice it has been found that wear occurs over a period of use. Also, in some instances the dimensions of the gauging portions are'slightly more or less than the dimensions to which the workpiece bore is intended to be .honed. Under such conditions the bore Will be honed oversize or undersize. In accordance with the present invention means is .provided for varying the pressure of the spring acting against the gauge means so as to compensate for wear of the gauge portions or variations in the sizing dimensions thereof. Where wear occurs the pressure of the spring may-be lessened or relieved so as to retard the entry of the gauge into the bore or cause it to enter less rapidly, therebyiprolonging somewhat the honing operation and preventing the bore from being honed undersize to an undesirable extent. If, on the other hand, the gauge dimensions are oversize or a condition prevails in which the bore is being honed undesirably oversize, the spring pressure may be increased so as to cause the spring to force the gauge into the bore more quickly or, in other words, accelerate its entry into the bore to interrupt the honing operation and prevent honing of the bore oversize to an undesirable extent.

The gauge device in the present embodiments is mounted around the reciprocable and rotatable spindle. The construction is such that the gauge device is shiftable axially with the spindle and also relatively thereto against the action of the compression spring when the gauge is unable to enter the workpiece bore. However, in order to achieve the best results it is important that the gauge device be maintained against rotation in conjunction with the rotation of the spindle. Accordingly, a feature of my invention resides in the provision of means to prevent rotation of the gauge device although permitting reciprocable motion thereof bothwith and relatively to the spindle. Gne way of accomplishing this is herein illustrated and involves the utilization of the limit switch trip arm or other member, attached to the gauge device,'as a means shiftable relatively to but engageable with a fixed abutment on the machine for holding the gauge device against rotation.

A further feature of my invention resides in the provision of guide means mounted on the abrading head and associated with the abrading members for-mounting or holding the workpiece in a true positionrelfititteio the Q3 honing tool as well as the abrading members. The provision of such guide means is particularly advantageous in honing the bores of connecting rods. The guide means may comprise members adapted to be moved radially and outwardly by wedge or tapered members under spring action so as to yieldingly engage the inner surface of the connecting rod bore during the honing operation thereby holding the connecting rod against rocking movement and maintaining its true and in proper axial relation to the tool spindle.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

A further important feature of the invention resides in the provision of an improved abrading device including a honing stone for use with a honing tool, said device affording better performance and materially longer stone life than heretofore. The honing stone has a front leading face, a rear trailing face and opposite end faces, these faces terminating at their outer edges in a working face. The abrading device has partial stone confining means, such as a preformed unitary plastic holder or casing means, including a backing layer extending over and secured to the rear trailing face of the stone and end layers extending over and secured to substantial portions of the opposite end faces of the stone. During the honing operation these backing and end layers are progressively removable with the working face of the stone during the honing operation. It will be seen that the front leading face or lead side of the stone from its juncture with the forward edge of the working face of the stone has the major area thereof open and exposed. Thus, when the abrading device is mounted in the rotatable honing tool support therefor, the front leading face or lead side of the honing stone faces in the direction of rotation of this support. Hence, during operation the wiping action of each stone will accumulate coolant and subject the lead side at the working face of the stone, to coolant action where the greatest heat is generated. The coolant will also penetrate more effectively into the stones, due to their porosity, thereby improving the cutting action and prolonging the life of the stones.

Fig. l is a view mainly in section illustrating a honing apparatus constructed in accordance with one embodiment of the present invention.

Fig. 2 is a section taken substantially through lines 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a perspective view of one of the abrading elements or honing stone assemblies incorporated in the apparatus shown in Fig. 1.

Fig. 4 is a section taken substantially through lines 4--4 of Fig. 3 looking in the direction. of the arrows.

Fig. 5 is an enlarged fragmentary view, partly in section, of the structure shown within the circle 5 of Fig. 1.

Fig. 6 is a view generally similar to Fig. 1 illustrating a honing apparatus constructed in accordance with a further embodiment of the invention.

Fig. 7 is a left-hand view of the structure shown in Fig.6.

Fig. 8 is a section taken substantially through lines 8-8 of Fig. 6 looking in the direction of the arrows.

Fig. 9 is an enlarged fragmentary View, mainly in section, illustrating particularly the guide means for controlling the position of the workpiece.

Before a detailed explanation of the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of'limitation.

This application is a continuation in part of my application Serial No. 390,555, filed November 6, 1954.

In the embodiment of Figs. 1 to 5 inclusive there is illustrated a honing tool or apparatus which is attachable at its inner or driven end to the conventional machine spindle. The honing tool, depending upon the type of machine with which it is used, may extend either vertically, or at an angle such as 45, or horizontally. In the present instance the tool is shown in a horizontal position, although it is understood that this is merely for illustrative purposes.

In accordance with the present embodiment the honing tool is provided with a tubular both or honing tool spindle 10 provided at its outer or lower end with an abrading head 10a which, in the present instance, is formed integrally with the spindle. The inner or machine end of the spindle 10 is indicated at 10b. For the purpose of drivingly connecting the tool to the machine spindle there is provided an attaching collar 11 mounted on the inner end 1% of the tool spindle and provided with internal threads 11a adapted to be screwed onto the nose of the machine spindle (not shown). Also mounted on the tool spindle 19 is a tool spindle driving sleeve 12 having a driving flange 12:: having a hole or slot 13 to receive the machine spindle driving pin and by means of which the sleeve 12 is driven. The sleeve 12 is rigidly attached to the spindle 10 such as by means of one or more locking or set screws 14.

Mounted around the body of the spindle 10 is a ball race ring 15 which is connected to the spindle by means of a Woodrutf key 16, the key extending into a longitudinal keyway in the ball race to permit the latter to be shifted axially relative to the spindle. A second ball race ring 17 is positioned in juxtaposed relation to the ball race 15 and interposed between these ball races are anti-friction ball bearings, as shown in Fig. l. A compression spring 18 encircles the spindle 10 and has its inner end in engagement with the ball race ring 17. The outer end of this spring abuts against a bearing sleeve 19 which is freely mounted on the spindle. It will be understood that the ball race ring 15 need not be keyed at 16 to the spindle but may have a bearing directly on the spindle and be free thereon for movement relative to the spindle. This construction, however, will not affect the operation of varying the pressure of spring 18 through the medium of the adjustingcollar hereinafter described.

Freely mounted on the ball race ring 15 is a trip arm sleeve 21). Attached to the inner end of this sleeve is a limit switch trip arm 21 which, as later described, is shiftable longitudinally with the sleeve 20 but held against rotation in conjunction with the tool spindle. The outer end of the sleeve 20 has an internal annular shoulder, see Fig. 1, abutting a flange portion on the bearing sleeve 19 which in turn abuts against an internal retaining ring 22 anchored in the sleeve 20. The bearing sleeve or collar 19 has a tight fit in the sleeve 20 and, therefore, along with the sleeve 20 and trip arm 21 does not rotate with the tool spindle. The ball race 15, which rotates with the tool spindle, is preferably given a hard chrome plated surface on which the non-rotatable sleeve 20 has a bearing. The non-rotatable collar or bearingsleeve 19 has a similar bearing on a chrome plated surface of the tool spindle for wear resistant purposes. Since the compression spring 18 is held under compression between the ball race ring 17 and the collar 19, the friction between the inner end of the spring and the ring 17 will tend to keep this ring fr'om'turning in view'of the ball bearings interposed between the ball races 15 and 17. This construction, which prevents any substantial turning of the spring, affords more efficient spring action. A stop ring 23 is attached to the spindle 1t) and acts as a limit not only for the travel of the collar 19 but also for the retractive movement of the gauge ring or sleeve hereinafter described.

ammo? Mounted on the sleeve 20 isagauge'ring adapterot support sleeve 24 which has internal threads engaging external threads on the sleeve 20: The threaded connection between the sleeves 20 and 24 provided adjusting means by which the axial position of the adapter sleeve 24 may be varied, thereby varying the axial position of the gauge or sizing ring, hereinafter described. The sleeve 24 is held in adjusted position by means of a spanner nut 25 threaded onto the sleeve 20.

The sleeve 24 is provided at its outer end with an inwardly projecting boss or enlargement Zea formed with internal threads into which is screwed a lock nut or ring 26. The portion 241: of the sleeve 24' is provided with aninwardly projecting retainer flange 27 and the opposed faces of this flange and the lock ring 26 are separated to provide an annular space or channel 28.

The honing tool is provided with gauge or sizing means 29 which includes a cylindrical body member 29:: freely embracing the spindle and shiftable axially relative thereto. This body member, which is in the form of a ring or sleeve, is formed with an annular flange 29b freely projecting into the channel 28 between the locking ring 26 and retainer flange 27. The width of the annular channel or space 23 slightly exceeds the thickness of the flange 29b and is sui'iicient to permit the flange to shift laterally or transversely of the spindle without appreciable frictional resistance within the channel 28. The internal diameter of the sizing ring or sleeve 29a is appreciably greater than the external diameter of the spindle at the locality of the sizing ring so as to permit the gauge ring or sleeve to shift or float laterally relative to the spindle a substantial amount, such as from ten to thirty thousandths of an inch depending upon the type of work being honed. The amount of float of the sizing device is indicated for illustrative purposes by the float space 30 in Fig. and also the space between the outer edge of the gauge ring flange 29b and the base of the channel 23.

The outer end of the sizing ring or gauge body 29a is machined to provide preferably four equally and annularly spaced longitudinal slots or grooves 31. Cemented or otherwise anchored in these grooves or slots are hardened or wear resisting gauge inserts or gauging elements 32 which may be in the form of carbide tips which project radially a slight distance outwardly of the gauge body. The inner portions of the gauge inserts, or the upper portions thereof when the tool extends vertically, are accurately machined to provide arcnate gauging or sizing surfaces 32a. The outer diameter across each pair of opposed gauge inserts corresponds to the desired diameter of the finished bore B of the workpiece W. For illustrative purposes the workpiece in the present embodiment is shown as a planetary gear. The inserts or gauge elements 32 terminate in tapering lead portions or lead means 32b which progressively narrow in effective diameter and, hence, are adapted to enter in varying amounts the unfinished bore of the workpiece. From the fore oing construction it will be seen that the gauge or sizing device 29 is entirely free to float or shift a predetermined amount laterally or transversely of the spindle thereby to compensate for uneven stone wear or misalignment of the longitudinal axis of the tool spindle with the longitudinal axis of the bore 3 of the workpiece W being honed.

The abrading head 16a, formed in the present instance as an extension of the tool spindle, is machined to provide through slots having curved ends, three of these slots being provided as shown in Fig. 2. Freely extending through these slots are abrading elements or members 35, see particularly Figs. 3 and 4. Each abrading element comprises a stone holder having an abrading stone cemented or otherwise mounted therein. The stone holder in the resent instance is in the form of a shell or casing 36 of thermoplastic material having a tapered bottom surface or Wall 36a and terminating in curved or arcuate ends 36b. The body of the stone holder is molded to provident longitudinal recess or elongate. notch. 31 inter: mediate the ends of theshell. This; recess hasrightangularly extending side and bottom surfaces, andii'sv closed by a relatively thin backing or suPPOrt wall 360.. cemented within the recess 37 of each stone holder is a square sided abrasive stone 38. This stone-is, exposed at its top or working face 38a and one longitudinal side face 38b thereof is also exposed between the ends of the stone holder. The opposite longitudinal side ofthe stone is covered by the backing wall 360. Eachstone holder is installed in the slots 34 of the abrading. head so that the exposed face or side 38b isdisposed or faces in the direction of rotation of the tool spindle, as shown in Fig. 2.

The abrading elements 35. are adapted to beexpanded.

radially or shifted outwardly by means of a cone; 39 having tapered slots 39a to receive the stoneholders. By

virtue of the cooperating tapered surfaces of the cone and stone holders outward shiftable movement of the cone will result in expanding the stone holders and contacting the working surfaces of the honing stones with the bore of the workpiece. The cone member 39 is connected by a pin 40 to a cone rod or shaft 41 extending freely through the tool spindle 10. The cone rod is provided at its inner end with a connector member or adapter piece 42 for attachment to the usual hydraulic mechanism of the machine which is operable to shift the cone rod axially of the spindle.

For the purpose of varying the pressure of the com pression spring 18 there is provided an adjusting collar 43 having internal threads engaging external threads. on the trip arm sleeve 12. The adjusting collar 43 abuts against the ball race ring is and may be locked in any axially adjusted position by means of a locking or set screw 44. By rotation of the collar 43 in one direction the collar will shift the ball race ring 15 outwardly or to the left in Fig. 1 thereby shifting the ball race ring 17 in the same direction and deflecting the spring 18 so as to increase the pressure or compression effort thereof against the collar 19. This increased spring eflort resulting from the adjustment of the collar 43 will augment the spring effort transmitted to the sizing ring or gauge 29 and accelerate the entry of the gauge inserts or elements 32 into the workpiece bore so as to interrupt the honing operation. On the other hand, if the adjusting collar 43 is turned in the opposite direction. so as to shift it a desired amount away from the ball race ring 15 the pressure of the spring will correspondingly move the ball race ring 15 and, hence, the effective pressure of the spring against the collar 1? will be lessened or relieved thereby retarding the entry of the gauge elements into the workpiece bore or cause them to enter less rapidly. In other words, by adjusting of the collar 43 in one direction to increase the pressure of the spring the gauge means will enter the bore more quickly to interrupt the honing operation and, hence, prevent honing of the bore oversize to an undesirable extent. Conversely, by adjustment of the collar 43 in the opposite direction to lessen the pres-sure of the spring the gauge means will enter the bore less rapidly thereby prolonging somewhat. the honing operation and preventing the bore from being honed undersize to an undesirable extent.

During operation it will be understood that the honing tool is reciprocated by the machine spindle toward and from the workpiece. As the abrading head 10a travels into the bore B being honed and the sizing gauge engages the end of the bore the tapered lead or camportions 32b of the gauge device, being of reduced. efiective diameter, will be able to enter the unfinished bore whereas the gauging portions 32a inwardly of the lead portions will notbe able to enter the bore until it is; finish honed to the desired size. When the bore diameter is too small to permit entry of the gauging or sizing portions 32a of the gauge the latter and the parts 24, 20 and 19.Wlll" be force inwardlyrelative to the spindle 10 and against "the Firmly resistance of the compression spring 18. 'As this occurs the spring will be increasingly compressed between the collar 19 and ball race ring 17. Thus, it will be seen that the action of the spring is to urge the sizing gauge in the direction of its entry into the workpiece bore. It will be apparent that where the honing tool is positioned horizontally the sizing gauge 29 will be disposed by gravity so that all of the float clearance or space 36 will be present at the lower side of the gauge device as shown in Fig. 5. As the gauge device contacts the end of the workpiece bore the gauge portions 3212 will first enter the bore. With the tool positioned horizontally as shown in Figs. 1 and S, the lead portion or portions of one or more of the gauge inserts and particularly the lower gauge insert as shown in Fig. 5, will due to the pressure of the spring engage the end of the bore will act in eifect to earn or shift the gauge member 2% transversely so as to center the member 29 with the center of the bore. With the tool positioned vertically a generally similar action occurs by engagement of one or more of the lead portions with the end of the bore so to cam or shift the gauge member transversely to a position centered with the axis of the workpiece whenever the axis of the spindle is out of alignment with the axis of the workpiece bore. This misalignment occurs in most instances and ordinarily varies from several thousandths to as much as approximately twelve thousandths of an inch. In Fig. 5 the axis of the gauge before entry into the bore is indicated at A land the axis of the workpiece is indicated at B. As soon as the lead portions 32b of the gauge elements 32 enter the bore the carnming action of one or more of the lead portions by engagement with the edge of the bore and by virtue of the pressure of the spring will displace the gauge member 29 so as to cause the axes A and B to coincide. It will be apparent, therefore, that, regardless of whether the tool operates horizontally or vertically, the gauge lead or cam portions will always function to displace the gauge ring or sleeve so as to substantially center it with the workpiece bore. Hence, when the bore has been honed to the correct size the action of the spring will force the gauge and its sizing portions fully into the here whereupon control means hereinafter described operates to interrupt or discontinue the honing operations.

From the foregoing it will be seen that by mounting the gauge so as to freely float transversely of the spindle 'it is possible to center the gauge with the workpiece bore and, hence, the gauge at the proper time will fully enter the bore when honed to the desired diameter thus eliminating the disadvantage of honing the bore to any "appreciable or objectionable oversize. The floating gauge not only compensates for spindle misalignment but also for 'uneven abrading stone wear which frequently occurs owing to the fact that the stones often vary in relative hardness.

In Figs. 6 to-9 inclusive there is illustrated a honing tool is provided with a tubular body or honing tool spindle 45 provided at its outer or lower end. with an abrading head 45a which, in the present instance, is formed integrally withthe spindle. The inner or machine end of the spindle is indicated at 45b. The honing tool is drivingly connected to the machine spindle through the medium of an attaching collar 46 provided with internal threads 46a adapted to be screwed onto the nose of the machine spindle (not shown). Also mounted on the tool spindle 45 is a tool spindle driving sleeve 47 having a driving flange 47a provided with a hole or slot 48 to;

8 receive the machine spindle driving pin and by means of which the sleeve 47 is driven. The sleeve 47 is rigidly attached to the spindle such as by means of locking pins 49.

Keyed to the sleeve 47 is a collar 50 which is held in fixed axial position between a retaining ring on sleeve 47 and a shoulder on the spindle 45. The collar 59 is provided with external threads engaged by internal threads on an adjusting sleeve 51 which may be adjusted axially on and relatively to the sleeve 50 in one direction or the other and held in adjusted position by means of a locking or set screw 52.

The adjusting sleeve or collar 51 abuts against a ball race ring or collar 53 which, although keyed to the spindle 45, is axially shiftable relative to the spindle as a result of adjusting of the adjusting collar 51. A second ball race ring 54 is positioned in juxtaposed relation to the ball race ring 53 and interposed between these ball races are anti-friction ball bearings, as shown in Fig. 6.

A trip arm sleeve 55 has a bearing and is freely mounted on the ball race rings 53 and 54. Threaded on the sleeve .55 is a trip arm ring 56 to which is attached a laterally projecting trip arm corresponding to the trip arm 21 in the previous embodiment. The ring 56 may be adjusted longitudinally of the sleeve 55 to adjust the position of the trip arm 21 and is held in adjusted position by means of a lock nut 58. The outer end of the sleeve 55 is formed with an inwardly extending spring retainer flange 55a "which has a free tit and a bearing on the spindle 45. In- .terposed betwen the flange 55a and the ball race ring 54 is a compression ring 59, this spring functioning in the same manner as the spring 18 in the previous embodiment. A stop ring 60 is attached to the spindle 45 and acts as a limit not only for the travel of the sleeve 55 but also for the retractive movement of the gauge ring or sleeve hereinafter described.

Threaded onto the sleeve 55 is an axially adjustable adapter sleeve 61 which may be adjusted longitudinally of the sleeve 55 in one direction or the other and held in adjusted position by means of a lock'nut 62. The sleeve 61 is provided with external threads and engageable therewith are the internal threads on an outer adapter sleeve 63 which i also adjustable longitudinally and held in adjusted position by means of a lock nut 64. A spacer 'ring 65 is interposed between the outer end of the sleeve 61 and an inwardly directed flange 6311 on the outer end of the adapter sleeve 63. This flange is formed with an annular groove forming with the spacer ring 65 an annular channel 66, similar to the channel 28 in the previous embodiment, which freely receives an annular flange 67a of a gauge or sizing ring or sleeve 67. As in the previous embodiment the flange 67a of the gauge member 67 is free within the annular channel 66 so as to permit the flange to shift laterally or transversely of the spindle within the channel without appreciable frictional resistance. The gauge ring or sleeve 67 is substantially the same as the gauge ring or member 29 and in like manner has an internal diameter appreciably greater than the external diameter of the spindle so as to permit the gauge ring or sleeve to freely shift or float laterally relative to the spindle in the same manner as described in connection with the gauge ring 29 in the previous embodiment. The amount of float of the gauge ring or sleeve 67 is indicated for illustrative purposes by the float space 65 in Fig. 6 and also between the outer edge of the gauge ring flange 67a and the base of the channel 66. The gauge ring or sleeve 67, as in the case of the gauge ring 2), is provided with four equally and annularly spaced longitudinal slots or grooves to receive gauge inserts 69 which correspond to the gauge inserts 32 of the previous embodiment and function in the same manner to gauge the diameter of the bore B of the workpiece W. In Fig. 6 the workpiece is illustrated as a connecting rod for an internal combustion engine.

The abrading head 450:, which forms an extension of the tool spindle, is slotted to receive a series, such as six, of annularly spaced abrading elements 70 which project into slots 71 in a cone member 72. The abrading elements 79 and the bottoms of the slots 71 have cooperating tapered faces, as in the previous embodiment, to provide for expansion or outward radial displacement of the abrading elements upon axial shiftable movement of the cone in the direction of the workpiece. Other than the fact that the abrading elements 70, each comprising a holder carrying an abrading stone, are shown in Fig. 6 as having less length than the abrading elements 35 of the previous embodiment, they are otherwise constructed, mounted and function in the same manner as previously described in respect to the abrading elements 35 in connection with Figs. 2, 3 and 4. with conventional practice the abrading elements are initially projected by the cone a relatively small amount outwardly of the abrading head and thereafter increasing amounts as stock of material are removed from the workpiece bore during the honing operation.

The cone 72 for expanding the abrading elements 70 is pinned at 73 to a cone rod or shaft 74 carrying at its inner end a connector member or adapter piece 75 for attachment to the usual hydraulic mechanism of the machine which is operable to shift the cone rod axially of the spindle.

The cone 72 is provided with a series, such as six, of longitudinal slots 76 which are disposed annularly of the cone in alternating relation to the slots 71 which receive the abrading elements, see Figs. 7 and 8. Extending within each of the slots 76 is a guide member 77 longitudinally slotted on its outer face to receive a carbide guide insert 78. Each guide 77 has a tapered inner face 77a engaged by the tapered face 79a of a wedge member 79. Freely mounted on the cone rod 74 is a spring retaining collar 89 which is disposed within a recess in the spindle body 45. The collar 80 is provided with an annular flange 80a which projects into slots 81 at the inner ends of all six of the wedge members 79. A compression spring 82 is interposed between the flange 80a of the collar 8t) and a spring retainer ring 83 positioned in abutting relation to a shoulder at the inner end of the recess in the spindle body. Pinned to the cone rod 74 adjacent the flange 80a of the spring retaining collar 80 is a retractor ring 84.

In the operation of the guide means for locating the workpiece and holding it true with respect to the abrading head, upon axial shifting of the cone 72 to expand the abrading elements 70 against the bore of the workpiece, the compression spring 82 will force the collar 80 in a corresponding direction and by virtue of the interlocking connection between the collar flange 80a and the wedge members 79 the latter will be shifted simultaneously with the cone and in the same direction. This axial movement of the wedge members 79 to the left in Figs. 6 and 9 will result in the wedge members shifting orexpanding the guides 77 outwardly so as to cause the guide inserts 73 to yieldingly engage the bore B of the workpiece. Thus, as the honing operation proceeds the guides will be yieldingly urged by the action of the spring .82 into contact with the surface of the workpiece bore thereby holding the workpiece in proper position. After the bore has been honed to the correct size and the honing operation is interrupted by entry of the gauge elements 69 into the bore the cone rod 74 will be retracted to collapse the abrading elements. Upon retraction of the cone rod the retractor member 84 will engage the collar flange 88a and also retract the wedge members 79 thereby collapsing the guide members 77 and releasing the pressure thereof against the bore of the workpiece.

It will be seen that the limit switch-trip arm 21 in each of the embodiments is attached to the gauge assembly and travels therewith axially of the tool. The gauge as- 24, 26 and 29 and in the embodiment of Fig. '6 includes In accordance parts 55, 61, 63 and 67. The gauge assembly in each instance travels" with the spindle toward the workpiece until the gauge elements contact the end of the unfinished workpiece bore, whereupon the gauge assembly backs up against the action of the compression spring. Upon finishing of the bore to size and entry of the gauge elements into the bore the entire gauge assembly is shifted by the action of the spring toward the workpiece and relative to the spindle. The trip arm 21 is provided at its outer end with a projection 21a engageable with and adapted to ride along the face of a fixed abutment or bracket 85 on the machine. By this construction the trip arm and, hence, the gauge assembly is held against rotation yet is permitted axial travel in opposite directions along the abutment in conjunction with the gauge assembly. The hydraulic mechanism for shifting cone shaft 41 is controlled by a limit switch generally indicated at 86 having a switch actuating member 87 in position to be engaged and tripped by the trip arm- 21, upon entry of the sizing or gauge elements into the workpiece bore, thereby electrically actuating a suitable solenoid control valve (not shown) to reverse the hydraulic circuit in the hydraulic mechanism and cause the same to retract the cone rod 41 and permit collapse of the abrading elements. Suitable adjusting means is provided, as indicated generally at 88, for adjusting axially of the tool the position of the limit switch thereby to vary the timing of the actuation of the switch by trip arm 21.

I claim:

1. In a honing apparatus for honing the bore of a tubular workpiece, said apparatus having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereor", a reciprocable annular gauge device embracing said spindle means and shiftable therewith toward and from the end of the workpiece through which the honing means enters to hone the bore of the workpiece, said gauge device having sizing means engageable with said end of the workpiece and adapted to operatively enter the workpiece bore when honed to a predetermined size, means for mounting said gauge device for limited but substantially free movement transversely of the spindle means to compensate for misalignment of the spindle means and work-piece and substantially center the gauge device with the workpiece, spring means acting on said gauge device and adapted to be compressed upon predetermined movement of the reciprocable means relative to the gauge device, and means operatively associated with said spring means for increasing or decreasing the spring effort exerted by said spring means against said gauge device to urge the sizing means thereof into the workpiece bore.

2. In a honing apparatus for honing the bore of a tubular workpiece, said apparatus having reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a reciprocable annular gauge device embracing said spindle means and shiftable therewith toward and from the end of the workpiece through Which the honing means enters to hone the bore of the workpiece, said gauge device having sizing means engageable with said end of the workpiece and adapted to operatively enter the workpiece. bore when honed to a predetermined s ize, spring means acting on said gauge device and adapted to be compressed upon predetermined movement of the reciprocable means relative to the gauge device when the latter is inelfective to enter the unfinished bore, and means operatively associated with said spring means for increasing or decreasing the spring efi'ort exerted by said spring means against said gauge device to urge the sizing means thereof intothe workpiece bore.

3. In a honing apparatus for honing the bore of a tubular workpiece, said apparatus having reciprocable and rotatable spindle means and honing means mounted adjacent one .end thereof, an annular gauge device encircling .s'aid spindle means and shiftable therewith toward and from the endof the workpiece through which the honing .meansienters to hone the bore of the workpiece, said gauge device having sizing means adapted to enter the workpiece here when honed to a predetermined size, means for mounting said gauge device for limited but substantially free movement transversely of the spindle means to compensate for misalignment of the spindle means and workpiece and substantially center the gauge device with the workpiece, spring means acting on said gauge device and adapted to be compressed upon predetermined movement of the reciprocable spindle means relative to the gauge device, and means associated with said spindle means and adjustable toward and from said spring means for increasing or decreasing the spring effort exerted thereby against said gauge device to urge the sizing means thereof into the workpiece bore.

4. In a honing apparatus for honing the bore of a tubular workpiece, said apparatus having a reciprocable and rotatable spindle means and honing means mounted adjacent one end thereof, a gauge device associated with said spindle means and shiftable therewith toward and from the end of the workpiece through which the honing means enters to hone the bore of the workpiece, said gauge device having sizing means adapted to enter the workpiece bore when honed to a predetermined size, spring tmeans acting on said gauge device and adapted to be compressed upon movement of the reciprocable means relative to the gauge device, and means associated with said spindle means and adjustable toward and from said spring means for increasing or decreasing the spring effort exerted thereby against said gauge device to urge the sizing means thereof into the workpiece bore.

5. in a honing apparatus for honing the bore of a workpiece, said apparatus having reciprocable and rotatable spindle means and honing means mounted at one end thereof, a plug gauge assembly embracing said spindle vmeans and shiftable therewith and also relative thereto, I said gauge assembly having gauge means engageable with w the end of the workpiece bore through which the honing means enters to hone said bore, said gauge means being adapted to enter the finished bore but ineffective to enter the unfinished bore, spring means associated with said spindle means and actuated thereby to urge the gauge assembly in the direction of entry of the: gauge means into the workpiece bore and adapted to be compressed upon travel of the spindle means relative to the gauge assembly consequent to the ineffectiveness of the gauge means to enter said bore, and means for varying the effort exerted by said spring means on the gauge assembly.

6. In a honing apparatus for honing the bore of a work piece, said apparatus having reciprocable and rotatable spindle means and honing means mounted at one end thereof, a gauge assembly embracing said spindle means and shiftable therewith and also relative thereto, means for mounting said gauge assembly for limited but substantially free movement transversely of the spindle means to substantially center the gauge means with the workpiece bore, said gauge assembly having gauge means adapted to enter the end of the finished bore through which the honing means enters but ineffective to enter the unfinished bore, spring means associated with said spindle means and actuated thereby to urge the gauge assembly in the direction of entry of the gauge means into the workpiece bore and adapted to be compressed upon travel of the spindle means relative to the gauge assembly consequent to the ineffectiveness of the gauge means to enter said bore, and means for varying the elfort exerted by said spring means on the gauge assembly.

7. In a honing apparatus for honing the bore of a work piece, said apparatus having reciprocable and rotatable spindle means and honing means mounted at one end thereof. a plug gauge assembly embracing said spindle means and shiftabie therewith and also relative thereto, said gauge assembly having gauge means engageable with the end of the workpiece bore through which the honing means enters to hone said bore, said gauge means being adapted to enterthe finished here but inefiective to enter "12 the unfinished bore, a compression spring embracing said spindle means and interposed between a part on said spindle means and a part on said gauge assembly and adapted to be compressed upon relative axial movement of the spindle means and gauge assembly when the gauge means is ineffective to enter the workpiece bore, and means adjustable toward and from said spring for increasing or decreasing the spring efiort exerted thereby against the gauge assembly to urge said gauge means into said bore.

8. In a honing apparatus for honing the bore of a workpiece, said apparatus having reciprocable and rotatable spindle means and honing means mounted at one end thereof, a gauge assembly embracing said spindle means and axially shiftable therewith and also axially relative thereto, means for maintaining said gauge assembly against rotation with said spindle means, said gauge assembly having gauge means adapted to enter the finished bore but ineffective to enter the unfinished bore, a compression spring embracing said spindle means and interposed between a part on said spindle means and a part on said gauge assembly and adapted to be compressed upon relative axial movement of the spindle means and gauge assembly when the gauge means is ineffective to enter the workpiece bore, and means adjustable toward and from said spring for increasing or decreasing the spring elfort exerted thereby against the gauge assembly to urge said gauge means into said bore.

9. In a honing apparatus, reciprocable and rotatable tubular spindle means, a honing head mounted at one end thereof, annularly spaced abrading elements carried by the head for radially shiftable movement, cone means axially shiftable in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements mounted in the head for radially shiftable movement, axially shiftable wedge members cooper-able with said guide elements, a shiftable cone rod extending axially and freely into said spindle means and connected at its outer end to said cone means for axially shifting the same, a collar member freely mounted on said cone rod and disposed within a recess in said spindle means, said collar member being connected to said wedge members, and a compression spring disposed in said recess between an abutment portion of said spindle means and said collar member and adapted to move the latter axially to shift said wedge members and thereby shift said guide elements gadially into yieldable engagement with the workpiece ore.

10. In a honing apparatus, reciprocable and rotatable tubular spindle means, a honing head mounted at one end thereof, annularly spaced abrading elements carried by the head for radially shiftable movement, cone means axially shiftable in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements mounted in the head for radially shiftable movement, axially shiftable wedge members cooperable with said guide elements, a shiftable cone rod extending axially and freely into said spindle means and connected at its outer end to said cone means for axially shifting the same, a collar member freely mounted on said cone rod and disposed within a recess in said spindle means, said collar memberbeing connected to said wedge members,

a compression spring disposed in said recess between an abutment portion of said spindle means and said collar member and adapted to move the latter axially to shift (said wedge members and thereby shift said guide elements radially into yieldable engagement with the workpiece bore, and means on said cone rod operative upon retraction of the latter for shifting said collar member to retract said wedge members.

11. In a honing apparatus, reciprocable and rotatable tubular spindle means, a honing head mounted at one 7 end thereof, annularly spaced 'abrading elements carried by the head for radially shiftable movement, cone means axially shiftable in one directionfor radially shifting said abrading elements to engage a workpiece bore, guide elements mounted in the head for radially shiftable movement, axially shiftable wedge members cooperable with said guide elements, a shiftable cone rod extending axially and freely into said spindle means and connected at its outer end to said cone means for axially shifting the same, axially shiftable spring retaining means freely embracing said cone rod and connected to said wedge members, spring means disposed between a portion of said spindle means and said retaining means and adapted to move the latter axially to shift said wedge members and thereby shift said guide elements radially into yieldable engagement with the workpiece bore.

12. In a honing apparatus, reciprocable and rotatable tubular spindle means, a honing head mounted at one end thereof, annularly spaced abrading elements carried by the head for radially shiftable movement, cone means axially shiftable in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements mounted in the head for radially shiftable movement, axially shiftable wedge members cooperable with said guide elements, a shiftable cone rod extending axially and freely into said spindle means and connected at its outer end to said cone means for axially shifting the same, axially shiftable spring retaining means freely embracing said cone rod and connected to said wedge members, spring means disposed between a portion of said spindle means and said retaining means and adapted to move the latter axially to shift said wedge members and thereby shift said guide elements radially into yieldable engagement with the workpiece bore, and means on said cone rod operative upon retraction of the latter for shifting said retaining means to retract said wedge members.

13. In a honing apparatus, reciprocable and rotatable tubular spindle means, a honing head mounted at one end thereof, annularly spaced abrading elements carried by the head for radially shiftable movement, cone means axially shiftable in one direction for radially shifting said abrading elements to engage a workpiece bore, guide elements mounted in the head for radially shiftable movement, axially shiftable wedge members cooperable with said guide elements, a shiftable cone rod extending axially and freely into said spindle means and connected at its outer end to said cone means for axially shifting the same, a coil spring embracing a portion of said cone rod, an annular member engaged by the outer end of said spring, said member freely embracing said cone rod, means for connecting said annular member to said Wedge members to cause the latter under the action of said spring to shift the guide elements radially into yieldable engagement with the workpiece bore, and abutment means on said cone rod operative upon retraction of the latter for shifting said annular member to retract said Wedge members.

14. For use with a honing tool having a rotatable support provided with mounting means for an abrading device, said tool having means for rotating the support in one direction, an abrading device including a honing stone having a front leading face, a rear trailing face and opposite end faces, said faces terminating at the outer edges thereof in a working face, said device having partial stone confining means including a backing layer extending over and secured to the rear trailing face of the stone and end layers extending over and secured to the opposite end faces of the stone, said backing and end layers being progressively removable with the working face of the stone during the honing operation, said front leading face 14 of the stone from its juncture with the forward edge of the working face of the stone having the major area thereof open and exposed, said abrading device being adapted to be mounted on said mounting means with said front leading face of the honing stone facing in the direction of rotation of said support.

15. For use with a honing tool having a rotatable support provided with mounting means for an abrading device, said tool having means for rotating the support in one direction, an abrading device including a honing stone having a front leading face, a rear trailing face and opposite end faces, said faces terminating at the outer edges thereof in a working face, said device having partial stone confining means including end layers abutting and bonded to opposite end faces of the stone, and a backing layer bonded to the rear trailing face of the stone and being progressively removable with the working face of the stone during the honing operation, said front leading face of the stone from its juncture with the forward edge of the working face of the stone having the major area thereof open and exposed, said abrading device being adapted to be mounted on said mounting means with said front leading face of the honing stone facing in the direction of rotation of said support.

16. For use with a honing tool having a rotatable support and means for rotating the support in one direction, an abrading device adapted to be carried by said support and including a honing stone having a front leading face, a rear trailing face and opposite end faces, said faces terminating 'at the outer edges thereof in a Working face, said abrading device having partial stone confining means comprising bottom and end layers overlapping the bottom and the opposite end faces of the said stone and secured thereto, a backing layer substantially covering and secured to the rear trailing face of the stone, said front leading face of the stone from its juncture with the working face of the stone having a substantial area thereof open and exposed, and said abrading device when carried by said support having the front leading face of the stone facing in the direction of rotation of said support.

17. An abrading device according to claim 14 wherein said partial stone confining means comprises a unitary holder preformed as a unit to provide a recess within which the honing stone is cemented.

18. An abrading device according to claim 14 wherein said partial stone confining means comprises a pre formed plastic holder molded as a unit to provide a recess within which the honing stone is cemented.

References Cited in the file of this patent UNITED STATES PATENTS 1,554,760 Restel Sept. 22, 1925 2,106,205 Connor Jan. 25, 1938 2,160,494 Floss May 30, 1939 2,164,811 Floss July 4, 1939 2,265,377 Kline Dec. 9, 1941 2,318,830 Crompton May 11, 1943 2,581,601 Peden Jan. 8, 1952 2,751,726 Klein June 26, 1956 FOREIGN PATENTS 613,962 Great Britain Dec. 7, 1948 1,088,452 France Sept. 8, 1954 

